Dragon Force (竜の力 (ドラゴン・フォース), Doragon Fōsu lit. Dragon's Power) is an advanced Dragon Slayer ability.
When a Dragon Slayer enters Dragon Force, they effectively turn into a humanoid Dragon, gaining reptilian scales and traits, such as further elongated, and sharper, canines and scale-like patterns on their skin. According to Zero, Dragon Force is the final, most powerful state a Dragon Slayer can attain; granting them power comparable to that which a real Dragon possesses: the power to utterly destroy everything.
Dragon Force greatly increases the damage done by standard Dragon Slayer spells, and grants the user access to more advanced, powerful attacks. It also drastically enhances the user's physical prowess, making them far stronger, more resistant to damage, and faster, and considerably boosts their Magic Power, which becomes visible, taking the appearance of a Dragon. When exuded at its fullest, said Magic Power takes on a violent corporeality, likely as a result of the immense amount of Magic power employed When Natsu Dragneel entered this state through the use of Jellal Fernandes' Flame of Rebuke, his flames gained the ability to burn off offending Magic, even that of Zero's ultimate attack Genesis Zero.
- For First Generation Dragon Slayers (初代滅竜, Shodai Metsuryū), those who have been taught their Magic by a real Dragon, certain conditions must be met in order to enter Dragon Force: the only one known so far would be to eat substances with powerful Magical properties, preferably those somehow related to the element they can control and consume; while other, unrelated substances can be eaten as well, these have been described as being similar to "poison" for the user, causing heavy after effects, such as pain on activation and extreme exhaustion after use. So far, Natsu Dragneel and Wendy Marvell are the only First Generation Dragon Slayers to have entered Dragon Force, doing so on three occasions: Natsu's first through the consumption of Etherion, and then Jellal Fernandes' Flame of Rebuke, while Wendy through eating air with an extremely high Eternano concentration. So far, Natsu and Wendy are the only known First Generation Dragon Slayer who has entered Dragon Force without outside stimulus in the canon universe.
- For Second Generation Dragon Slayers (二代滅竜, Nidai Metsuryū), those who have obtained their powers by implanting Dragon Lacrima in their body, Dragon Force mode is seemingly entered whenever they make use of their Dragon Slayer Magic. However, due to this easiness to achieve this form, their powers don't seem to be increased at the same level of Old-Style Dragon Slayers, with no dragon-like aura appearing for them. Laxus Dreyar and Cobra have been shown achieving such state.
- For Third Generation Dragon Slayers (三代滅竜, Sandai Metsuryū), those who have not only been taught by a Dragon but also have Dragon Lacrima implanted into their body, are capable of freely entering Dragon Force. However, the appearance of their Dragon Force is slightly different from the previous generations, for instead of actual scales, a scale-like design appears on their face and body.
- Before Dragon Force was officially named, fans refereed to this transformation as "Dragon Slayer Mode."
- Currently all Second Generation Dragon Slayers have Dragon Force activated when ever they perform Dragon Slayer magic.